1. Field of the Invention
The present invention relates to an image synthesizing scope for synthesizing and displaying two image and an image synthesizer using such an image synthesizing scope.
2. Description of the Related Art
There is known an image synthesizing technique which synthesizes and displays two images using a half-mirror. Such a technique is described, for example, in Japanese Utility Model Laid-Open No. Sho 62-89689 or Japanese Patent Laid-Open No. Sho 60-84573.
The former discloses a display system which comprises a half-mirror providing two optical paths and a video monitor located in one of the two optical paths, the other optical path receiving an object to be displayed. A scene in the video monitor is superimposed on the object.
The latter discloses another display system which comprises a half-mirror 2 disposed in front of an observer M, as shown in FIG. 12. An image is projected from a projector 3 located on the side of the observer M to form a reflective image. An object 5 is positioned on the opposite side to the observer M and viewed through the half-mirror surface. The reflective image is superimposed on the viewed image of the object 5. Thus, various images can be combined and displayed. This is very effective in advertisement, education and other fields.
As will be apparent from the foregoing, the prior art is adapted to display a composite image which is obtained by super-imposing a stationary object on a moving scene. This can provide a visually improved effect which is obtained from the combination of an actual object with a moving scene.
However, the prior art can only provide a composite image within a range of display which is limited by the ability of CRT or the like. If the object 5 is a larger one or if the object 5 is located over a relatively large space, the prior art cannot synthesize and display a composite image which is obtained by superimposing the scene on the large space.
The prior art can provide any motion only on the side of the moving scene since it is the stationary object which is superimposed on the moving scene.